Why does Subaru engine knock after turned off?

Subaru engine knock after being turned off can occur due to a phenomenon known as "dieseling," where the engine continues to run briefly after the ignition is turned off. This can happen if there are hot spots in the combustion chamber that ignite residual fuel. Additionally, factors like carbon buildup or an overly rich fuel mixture can contribute to this issue. Regular maintenance and ensuring the engine is tuned properly can help mitigate this problem.